From 7 December 1941, the date of the Japanese attack on Pearl Harbor, to 31 August 1945, two days before the Japanese surrender at Tokyo Bay, Pacific Fleet staff at Pearl Harbor maintained a running estimate and summary of communicatons and other records in a “gray book,” copies of which were filed with the papers of Fleet Admiral Chester W. Nimitz at the Operational Archives, Naval History and Heritage Command, Washington Navy Yard, Washington D.C.

This digitization was carried out in 2012 as a cooperative effort between the Naval War College and the Naval History and Heritage Command. It was overseen by the Naval War College Library. Funding was provided by the Naval War College Foundation, Newport, Rhode Island, with donations received from the Naval Order of the United States and several individual Foundation members.